Methods and apparatus for securing medical instruments to desired locations in a patient&#39;s body

ABSTRACT

Devices and methods are provided for securely affixing a medical instrument to desired tissue in a patient&#39;s body, using a fixation agent. Such medical instruments may comprise localization wires or tissue acquisition instruments, such as biopsy instruments, for example. In the case of tissue acquisition instruments, the inventors have discovered significant advantages for securely affixing the distal end of the tissue acquisition instrument to a particular tissue target area. For example, such an approach permits the imaging environment to be uncoupled from the procedural environment so that expensive and often unavailable imaging equipment, such as stereotactic imaging equipment, need not be used. In a preferred embodiment, a bonding agent, such as adhesive, surgical glue, or a solvent, is used as the fixation agent.

FIELD OF THE INVENTION

The present invention relates to methods and devices for ensuring that amedical instrument remains in a desired location within a patient's bodyduring a medical procedure, and more particularly to methods and devicesfor affixing a distal end of the medical instrument to the desiredlocation using adhesives.

BACKGROUND OF THE INVENTION

It is often desirable and frequently necessary to sample or remove aportion of tissue from humans and other animals, particularly in thediagnosis and treatment of patients with cancerous tumors. pre-malignantconditions, and other diseases or disorders.

Typically, in the case of cancer, particularly cancer of the breast,there is a great emphasis on early detection and diagnosis through theuse of screening modalities, such as physical examination, andparticularly mammography, which is capable of detecting very smallabnormalities, often nonpalpable. When the physician establishes bymeans of a mammogram or other screening modality, such as ultrasound,that suspicious circumstances exist, a biopsy must be performed tocapture tissue for a definitive diagnosis as to whether the suspiciouslesion is cancerous. Biopsy may be done by an open or percutaneoustechnique. Open biopsy is a surgical procedure using a scalpel andinvolving direct vision of the target area, for removing the entire mass(excisional biopsy) or a part of the mass (incisionial biopsy).Percutaneous biopsy, on the other hand, is usually done with aneedle-like instrument through a relatively small incision, blindly orwith the aid of an artificial imaging device, and may be either a fineneedle aspiration (FNA) or a core biopsy. In FNA biopsy, individualcells or clusters of cells are obtained for cytologic examination andmay be prepared such as in a Papanicolaou smear. In core biopsy, as theterm suggests, a core or fragment of tissue is obtained for histologicexamination which may be done via a frozen section or paraffin section.

The type of biopsy utilized depends in large part on circumstancespresent with respect to the patient, including the location of thelesion(s) within the body, and no single procedure is ideal for allcases. However, core biopsy is extremely useful in a number ofconditions and is being used more frequently by the medical profession.

When an open surgical biopsy procedure is indicated, current practicedictates the use of lesion localization needles and devices, commonlyreferred to as “localization wires”, for use in localizing or markingnon-palpable lesions and tumors within the body. These devices generallycomprise a hypodermic needle or cannula which is inserted into the bodyunder local anesthesia to the lesion or tissue of interest. The wiremarker, or localization wire, is then passed through the cannula andextends through the lesion of interest so that the distal end thereof isanchored beyond the lesion. Thus, the lesion is marked for subsequentsurgical procedures such as excision or biopsy. The anchoring procedureis typically accomplished by means of mechanical structure disposed atthe distal end of the wire marker, such as a barb, hook, or the like,which is attached to surrounding tissue. After marking the lesion withthe wire marker, the cannula is usually removed from the body, leavingthe wire in place and extending from the body, for subsequent use by thesurgeon during the biopsy procedure in identifying the lesion location.However, it often occurs that the barb or hook at the distal end of thewire marker attaches to something other than the tumor or lesion. Forexample, in the case of breast biopsies, the breast will typically beplaced in compression during the imaging procedure in order to properlyidentify the location of the target lesion and place the. localizationwire. However, breast tissue is comprised of fibrous bands which, incompression, may be close to the target lesion and inadvertently engagedby the barb of the localization wire. Later, when the breast is releasedfrom compression prior to the surgical procedure, the fibrous bands willmove away from the target lesion, and the distal end of the localizationwire may thus move a substantial distance away from the target lesion.

It would be desirable, therefore, to develop a localization wire systemand method wherein the distal end of the localization wire could bepositively attached to the target lesion in order to minimize thepossibility of migration of the distal end of the localization wire awayfrom the target lesion between the imaging and surgical procedures.

In circumstances where a core biopsy procedure is indicated, varioussystems are available. Such systems are shown, for example in U.S. Pat.No. 5,526,822 to Burbank et al, which discloses a probe having alaterally disposed tissue receiving port at the distal end thereof foracquiring relatively small tissue samples, and in U.S. Pat. No.5,111,828 to Kornberg et al., which discloses a probe having an axiallydisposed tissue receiving port at the distal end thereof for acquiringrelatively large intact tissue samples. Both of these patents areexpressly incorporated by reference herein.

U.S. application Ser. No. 09/057,303 to Burbank et al., commonlyassigned with the present application and expressly incorporated byreference herein, discloses still another core biopsy apparatus, whichadvantageously permits the acquisition of tissue samples which arelarger in diameter than the diameter of the instrument lumen, therebygreatly increasing the chances of completely removing the target lesionand leaving “clean” margins thereabout.

As in the case of localization wires, there is some risk in using any ofthe foregoing devices that the distal end of the instrument will migrateaway from the target lesion during the biopsy procedure, therebyreducing the likelihood of removing target tissue. Heretofore, in thecase of core biopsy procedures, the risk of this occurrence is minimizedby employing image guidance techniques during the entire tissue removalprocedure. For example, in the case of the '822 Burbank et al. patent, astereotactic imaging guidance system is typically utilized during thedisclosed procedure. One disadvantage of this approach, however, is thatthe patient's breast must remain in compression during the entireprocedure, with attendant discomfort and increased proceduraldifficulty, in order to properly utilize the imaging equipment.Furthermore, stereotactic imaging equipment or other suitablealternatives can cost as much as $400,000 or more and is not in theusual inventory of a typical community hospital. It would therefore bequite advantageous if a method and apparatus could be developed whichwould permit the uncoupling of the imaging environment from theprocedural environment without undue risk that the active or cutting endof the core biopsy instrument would migrate away from the target lesionduring the interval between the imaging procedure and the biopsyprocedure.

SUMMARY OF THE INVENTION

The present invention solves the problems outlined above by describingdevices and methods for securely affixing a localization wire to desiredtissue in a patient's body, so that after the patient is moved from theimaging environment to the procedural environment, the practitioner willhave assurance that the localization wire is still accurately placed.Additionally, devices and methods are described for ensuring that thedistal end of a tissue acquisition instrument, such as a biopsyinstrument, is securely affixed to a particular target area, such as alesion, in a patient's body, thereby advantageously permitting theimaging environment to be uncoupled from the procedural environment sothat expensive and often unavailable imaging equipment, such asstereotactic imaging equipment, need not be used.

More particularly, in one aspect of the invention a medical device isprovided comprising a tube having a distal end, a proximal end, and alongitudinal axis, wherein the device is adapted for placement of thedistal end thereof into a patient's body at a desired location. Themedical device includes a fixation agent, which may comprise any one ofa bonding agent, a mechanical fixation agent, or an electrosurgicalcoagulation element, disposed on the distal end thereof, which isadapted for affixing the distal end of the medical device at the desiredlocation.

The medical device may comprise, for example, a localization wire foruse in connection with an open biopsy procedure. Alternatively, thedevice may comprise a tissue acquisition instrument, such as a biopsyinstrument. In the preferred embodiment, the fixation agent is a bondingagent, comprising a surgical adhesive, glue, or solvent.

In another aspect of the invention, a tissue acquisition instrument isprovided for retrieving body tissue, having a longitudinal axis andwhich comprises a distal end adapted for entry into a patient's body, acutting element disposed on the instrument for cutting surroundingtissue, and structure disposed on the distal end for securing the tissueacquisition instrument at a predetermined desired location, in order toensure that the tissue acquisition instrument remains in place during atissue acquisition procedure so that desired tissue is properlyacquired.

In yet another aspect of the invention, a method of performing a medicalprocedure is provided, using a medical device comprising a tube having adistal end, a proximal end, and a longitudinal axis. The method firstcomprises the step of placing the distal end of the tube in a patient'sbody, so that the distal end is disposed in a desired tissue location.Then, a bonding agent is dispensed for the tube into tissue surroundingthe distal end, so that the distal end of the tube becomes affixed tothe desired tissue location.

In still another aspect of the invention, a method is provided forperforming a tissue acquisition procedure using a tissue acquisitioninstrument having a distal end, a proximal end, a longitudinal axis, anda cutting element. In this method, the distal end of the instrument isplaced into a patient's body, so that the distal end is disposed in adesired tissue location. Then, the distal end of the instrument isaffixed to the desired tissue location, so that the instrument does notmove relative to the desired tissue location during the tissueacquisition procedure. The cutting element is then actuated to acquireone or more tissue samples.

The invention, together with additional features and advantages thereof,may best be understood by reference to the following description takenin conjunction with the accompanying illustrative drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic plan view of a first embodiment of the presentinvention, illustrating a catheter for a localization wire introductionand infusion system wherein an introducer needle for introducing thelocalization wire into a patient's body remains in place duringsecurement of the localization wire to surrounding tissue using abonding agent;

FIG. 2 is a schematic plan view of the introducer needle used inconjunction with the catheter of FIG. 1;

FIG. 3 is a schematic plan view of one embodiment of a localization wirewhich may be used in conjunction with the infusion system shown in FIGS.1 and 2;

FIG. 3 a is a perspective view of the distal end of the embodiment shownin FIGS. 1-3, wherein the introducer needle is inserted through thelumen of the catheter;

FIG. 3 b is a perspective view of the distal end of the embodiment shownin FIGS. 1-3, wherein the introducer needle is inserted through thelumen of the catheter, and its position within the catheter lumen isshown in phantom for illustrative purposes;

FIG. 3 c is a perspective view similar to FIG. 3 a, wherein thelocalization wire is inserted through the lumen of the catheter;

FIG. 4 is a perspective view of a second embodiment of the presentinvention, illustrating a second embodiment of a localization wireintroduction and infusion system, wherein an introducer needle forintroducing the localization wire into a patient's body is removedduring securement of the localization wire to surrounding tissue using abonding agent;

FIG. 5 is schematic plan view of the catheter for the system illustratedin FIG. 4;

FIG. 6 is a schematic plan view of the introducer needle for the systemillustrated in FIGS. 4 and 5;

FIG. 6 a is a perspective view of the distal end of the embodiment shownin FIGS. 4-6, wherein the localization wire is inserted through a lumenof the catheter;

FIG. 7 is a schematic plan view of a second embodiment of a localizationwire which may be utilized in conjunction with either of the embodimentsof FIGS. 1-3 or 4-6;

FIG. 8 is a schematic view in isolation illustrating one embodiment ofthe present invention for storing and releasing a bonding agent which isdispensed from a medical instrument for affixing the medical instrumentto surrounding tissue in a patient's body;

FIG. 9 is a perspective view of a third embodiment of the presentinvention, illustrating a catheter which may be used as a localizationwire and infusion system;

FIG. 10 is an enlarged perspective view of the distal end of the cannulaillustrated in FIG. 9, showing in greater detail the perforations in thedistal end for infusing a bonding agent to surrounding tissue;

FIG. 11 is a perspective view of a modified version of the embodimentshown in FIGS. 9 and 10, wherein the cannula is comprised of a braidedpolymer tubing and the interstices between the braids function as theinfusion openings for infusing bonding agent to surrounding tissue;

FIG. 12 is a perspective view of another modified version of theembodiment shown in FIGS. 9 and 10, wherein the cannula is comprised ofa coil and the interstices between expanded coils function as theinfusion openings for infusing bonding agent to surrounding tissue;

FIG. 13 is a perspective view of a biopsy instrument constructed inaccordance with the principles of the present invention;

FIG. 14 is a perspective view of a second modified embodiment of abiopsy instrument having an expandable Mallicot structure at its distalend for anchoring the instrument at a particular tissue site;

FIG. 15 is a perspective view of a third modified embodiment of a biopsyinstrument having a modified expandable Mallicot structure at its distalend for anchoring the instrument at a particular tissue site;

FIG. 16 is a perspective view of a fourth modified embodiment of abiopsy instrument having an expandable linkage structure at its distalend for anchoring the instrument at a particular tissue site, whereinthe linkage structure is shown in its retracted position;

FIG. 17 is a perspective view of the embodiment shown in FIG. 16,wherein the linkage structure is shown in its expanded position;

FIG. 18 is a perspective view of a fourth modified embodiment of abiopsy instrument having an extendable “bottle brush” structure at itsdistal end for anchoring the instrument at a particular tissue site;

FIG. 19 is a perspective view of a fifth modified embodiment of a biopsyinstrument having a nitinol flap structure at its distal end, expandableupon retraction of a surrounding sleeve, for anchoring the instrument ata particular tissue site;

FIG. 20 is a perspective view of a sixth modified embodiment of a biopsyinstrument having a rolled stent structure at its distal end whichunrolls upon retraction of a surrounding sleeve, for anchoring theinstrument at a particular tissue site;

FIG. 21 is a perspective view of a seventh modified embodiment of abiopsy instrument having expandable spiral wires at its distal end foranchoring the instrument at a particular tissue site; and

FIG. 22 is a perspective view of an eighth modified embodiment of abiopsy instrument having an expandable basket at its distal end foranchoring the instrument at a particular tissue site.

DETAILED DESCRIPTION OF THE INVENTION

Referring now more particularly to the drawings, FIGS. 1-3 c illustratea first embodiment of the invention, wherein a medical instrument 10(FIGS. 3 a -3 c) comprises a catheter 12 (FIGS. 1, 3 a -3 c), anintroducer needle 14 (FIGS. 2, 3 a, and 3 b), and a localization wire 16(FIGS. 3, 3 c). In this embodiment, which may be styled as a “needle in”infusion system, the introducer needle 14 comprises a sharp distal end18, which is inserted through an entry hole 20 in the catheter 12 (FIG.1), so that its tip 18 extends beyond the distal end 22 of the catheter12, as shown in FIGS. 3 a and 3 b. The introducer needle 14 may includea stop 24 having an enlarged diameter, which is adapted to engage thedistally tapering inner sidewall of the catheter 12 at a predeterminedpoint, as generally shown particularly in FIG. 3 b, to ensure that thetip 18 properly extends beyond the distal end 22 of the catheter 12. Theintroducer needle 14 and catheter 12 together are then introduced into apatient's body (not shown), using known imaging techniques for guidinglocalization wires to the site of tissue to be excised (“targettissue”).

Once the catheter 12 and introducer needle 14 are in position relativeto the target tissue, the introducer needle 14 is removed proximallyfrom the catheter 12, and the localization wire 16 is inserted distallythrough the entry hole 20 and pushed distally through the lumen in thecatheter 12, so that the distal end of the localization wire 16 extendsdistally of the distal end of the introducer needle and catheter, asshown in FIG. 3 b. Indicator marks 25 preferably assist the practitionerin ensuring that the localization wire is properly inserted to therequired depth.

Localization wires such as the wire 16 typically include some-type ofmechanical anchoring means, such as a barb or hook 26, for securing thedistal end of the localization wire 16 in position behind the targettissue. However, this approach is often inadequate, as discussed suprain the Background portion of the specification, because the tissue towhich the hook 26 becomes attached will often shift relative to thetarget tissue between the imaging step of the medical procedure, whichis usually a biopsy, such as a breast biopsy, and the ensuing surgicalstep, which usually takes place in a different area of the hospital andrequires transportation and resultant jostling of the patient from theradiology department to the operating room. The present invention,therefore, contemplates an advantageous additional step of employing abonding agent, *which may comprise any known material which is capableof creating a bond between the distal end of the medical instrument 10and surrounding tissue. Once the localization wire is properly placed atthe desired target tissue site, under imaging guidance, the bondingagent is dispensed from the distal end of the medical instrument to thesurrounding tissue to create the desired bond. In the embodiment ofFIGS. 1-3 a, a plurality of infusion ports 28 are disposed along thelength of the distal end of the catheter 12. Any number of infusionports (one or more) may be employed in order to optimize the flow ofbonding agent to the tissue, and they are preferably staggeredcircumferentially about the catheter in order to evenly deliver bondingagent about the circumference of the instrument 10. Various deliverymeans may be employed as well. For example, in the illustratedembodiment, the catheter 12 comprises a proximal hub 30 (FIG. 1),including a stopcock 32 which is engageable with a syringe (not shown)containing the bonding agent. When the localization wire is properlypositioned, the practitioner injects the bonding agent into the lumen(not shown) of the catheter using the syringe with sufficient pressurethat it flows distally through the lumen and is infused into surroundingbody tissue through the infusion ports 28. The resultant bonding of thedistal end of the localization wire 16 to the surrounding target tissueensures with much greater certainty than the use of mechanicalattachment means alone, such as the hook 26, that the localization wirewill be properly positioned when the surgical procedure commences,thereby improving the likelihood that the proper target tissue will beexcised with a minimum incision and resultant trauma to the patient.

Preferred bonding agents include any known effective biocompatiblebonding materials, such as surgical adhesives, including cyanoacrylate,fibrin glue, and solvents.

An alternative to injection of the bonding agent through the lumen ofthe medical instrument 10 is illustrated in FIG. 8. The bonding agent 33may be stored in a rupturable container 34 which is disposed in thedistal end of the medical instrument 10, adjacent to the infusion ports28. When it is desired to release the bonding agent 33 through theinfusion ports, a puncturing device 36 may be actuated by thepractitioner to rupture the container 34. In the illustrated embodiment,the device 36 comprises a simple “spear” which is actuated distally torupture the container, but it may alternatively comprise any suitableconfiguration for functioning equivalently. Additionally, it is withinthe scope of the invention to employ a chamber for containing thebonding agent which includes a valved port, wherein the valve isactuated to an open position by the practitioner to release the bondingagent. Various other embodiments for accomplishing this function, aswould be known to one of ordinary skill in the art, are deemed to fallwithin the scope of the invention as well.

Once the localization wire is securely bonded to the surrounding tissue,the practitioner may withdraw the catheter and introducer needleassembly, leaving the localization wire in place to mark the targettissue for the ensuing surgical step in the biopsy or other medicalprocedure.

FIGS. 4-7 illustrate a second “localization wire” embodiment, whereinlike elements to those shown in the first embodiment are designated bylike reference numerals, succeeded by the letter “a”. This system may bestyled as a “needle out” infusion system. In this embodiment, thecatheter 12 a comprises a dual lumen extrusion, including first andsecond lumens 38 and 40, respectively (FIG. 6 a). The first lumen 38accommodates the bonding agent, while the second lumen accommodates thelocalization wire. The catheter 12 a further includes a dual lumenproximal hub 42, which comprises a localization wire entry port 44 and astopcock 32 a.

In operation, the introducer needle 14 a is disposed coaxially outsideof the catheter 12 a as illustrated in FIG. 4, and the instrument 10 ais inserted into the patient's body in known fashion, under conventionalimaging guidance. The localization wire 16 a is inserted distallythrough the port 44, either before or after introduction of theinstrument 10 a into the patient's body. As in the first embodiment,once the instrument 10 a is placed, the localization wire 16 a isadvanced distally until the indicator marks 25 a indicate to thepractitioner that the distal hook 26 a is distal of the distal end ofthe catheter 12 a and of the target lesion, as shown by the imagingequipment. The localization wires of FIGS. 3 and 7 may be usedinterchangeably in either of the two disclosed embodiments, and aresubstantially identical except that the localization wire 16 a includesfilaments 46 near its distal end which provide additional surface areafor bonding.

As in the previous embodiment, once the localization wire is in theproper position, bonding agent is injected into the catheter 12 a,preferably using a syringe which is engaged with the stopcock 32 a, sothat the bonding agent flows distally through the first lumen 38 and isinfused through the infusion ports 28 a. Again, the infusion ports maybe disposed about the catheter, in rows offset by 90 degrees withrespect to one another or otherwise staggered so that the bonding agentis evenly disposed about the catheter. Alternatively, as in the previousembodiment, the bonding agent may be stored in the distal end of theinstrument 10 a using an apparatus like that illustrated in FIG. 8. Itis within the scope of this invention, as well, to store or inject twoor more bonding agent compounds, comprising a reactant and a catalyst,at the injection site, and to mix the reactant and catalyst together atthe appropriate time to catalyze a bonding agent.

Once the bonding agent has been injected, but before it has solidified,the catheter 12 a and introducer needle 14a are withdrawn from thepatient's body, leaving the localization wire in place.

Still a third embodiment, which functions in a manner equivalent to thatof a localization wire is illustrated in FIGS. 9 and 10. In thisembodiment, a catheter 48, which comprises a proximal hub 50, a distalend 52, and a lumen 54, is insertable into a patient's body usingconventional image guidance techniques, so that the distal end 52 isdisposed at a desired target tissue site. Once properly located, abonding agent 33 is infused through one or more infusion ports 56 tosurrounding target tissue, in order to bond the distal end of thecatheter 48 to the surrounding tissue. Again, as in the previousembodiments, the bonding agent may be injected into the lumen 54 of thecatheter through the proximal hub 50, or may alternatively be stored inthe distal end 52 of the catheter and selectively released at thedesired time.

FIGS. 11 and 12 illustrate two alternative embodiments for the outertube 58 of the catheter in any of the foregoing embodiments. In FIG. 11,the tube 58 comprises a stainless steel braid, the proximal end 60 ofwhich is encapsulated by a polymer, such as polyamide, and the distalend 62 of which is exposed. The exposed distal end is preferablyapproximately 1-2 centimeter (cm) in length, though it may be longer orshorter if desired. In operation, interstices 64 between bands 66 of theexposed braided portion 62 function as openings for permitting infusionof bonding agent to surrounding tissue, instead of the infusion portsdisclosed in the preceding embodiments. If the exposed braided portionis expanded, the interstices will be enlarged and will permit the flowof more bonding agent therethrough.

In a manner in some respects similar to the embodiment of FIG. 11, theFIG. 12 embodiment comprises an outer tube 58 having a sleeve 68surrounding a coil 70 of suitable material. In the distal end of thetube 58, the coil 70 may be stretched to create interstices 72 betweenbands 74 of the coil. Bonding material may be infused, as desired,outwardly through the interstices 72 of the expanded coil, and thenthrough holes 76 in the sleeve 68 to surrounding tissue. Alternatively,the sleeve could be retracted to expose the coil, in which case thesleeve holes 76 would be unnecessary.

FIG. 13 illustrates the distal end of a medical instrument 78 which isshown and described in co-pending application Ser. No. 09/057,303,commonly assigned with the present application and expresslyincorporated by reference herein. The instrument 78 comprises a tissueacquisition or biopsy instrument and preferably includes a tip 80 havingan electrosurgical element 82 for entering tissue, and a shaft 84, onwhich is disposed a radially extendable and retractable cutting elementor wire 86. The cutting element 86 is preferably energized by RF energyprovided by an electrosurgical generator.

In operation, the instrument 78 is moved axially to a position whereinthe distal tip 80 is preferably distal to a target lesion or tissue tobe removed, using a suitable imaging technique. In the prior art, suchimaging techniques for biopsy procedures and the like typically includethe use of a stereotactic or sonographic imaging system, both of whichare relatively expensive and not always available in an averagecommunity hospital. This approach is designed to combine the imaging andcutting steps so that both occur simultaneously. For example, in thecase of a breast biopsy procedure, the breast is clamped in order toeffectively utilize the imaging equipment, after which the instrument isinserted into the breast under imaging guidance to the lesion location.Then, under continued imaging guidance, the cutting element is actuatedand the target tissue removed.

However, an important advantage of the present invention is the abilityto “uncouple” the imaging environment from the procedural environment ina typical surgical or biopsy procedure, and the resultant importantability to utilize unmodified mammography equipment, readily availablein most hospitals, to position the distal end of the instrument duringthe imaging step, rather than expensive and specialized stereotacticequipment. Then, the procedural step may occur later, in another area ofthe hospital. In the case of breast biopsies, this “uncoupling” alsopermits the patient's breast to be unclamped for the procedural step,resulting in increased patient comfort and easier working conditions forthe practitioner.

These advantages are made possible because the inventive apparatus andtechnique permits the securement of the distal end of the instrument tothe target tissue or lesion with sufficient confidence that the patientmay be moved to the procedural environment without fear of having itslip away from the target tissue. This securement is accomplished usinga fixation agent, which preferably comprises a bonding agent like thatdisclosed in connection with the foregoing localization wire andcatheter embodiments. In a manner similar to those embodiments, once theinstrument is positioned in a desired position, the bonding agent isinjected into a lumen of the instrument, or, alternatively, in a mannerlike that described supra, released from a container or chamber in thedistal end of the instrument, so that it may be infused from one or moreinfusion ports 88 disposed on the distal end of the instrument.Preferably, the ports 88 are disposed on a bushing or sleeve 90 whichhas a linear slot 92 for permitting passage of the cutting element 86 asit is extended and retracted radially, and which is rotatable relativeto the shaft 84. Thus, when the bonding agent is infused to thesurrounding tissue, so that the bushing 90 is affixed in place relativeto the surrounding tissue, the cutting element 86 will still berotatable on the underlying shaft 84 in order to permit circumferentialcutting of tissue, as desired, during the later procedural step.Suitable care is taken that only a sufficient amount of bonding agent isdispensed to bond the bushing to surrounding tissue, and not the shaftor tip of the instrument, in order that the shaft and tip continue to berotatable relative to the bushing.

Of course, the bushing 90 may be constructed in number of alternativeways, as will be apparent to those of ordinary skill in the art. Forexample, as shown in FIGS. 11 and 12, the bushing could be comprised ofa braided or coil material, so that interstices between braids or coilsthereof could function as the infusion openings.

Rather than using a bonding agent, a mechanical fixation agent may beutilized to secure the distal end of the instrument to surroundingtissue. For example, FIG. 14 illustrates an alternative embodiment tothat of FIG. 13, wherein a mechanical fixation structure 94 is utilizedto secure the distal end of the instrument to surrounding tissue, ratherthan a bonding agent. In this embodiment, wherein like elements to thoseof FIG. 13 are designated by like reference numerals, succeeded by theletter “b”, the mechanical fixation structure 94 comprises an expandableMallicot structure, having a rotatable bushing 90 b and a plurality ofexpandable bands 96. Actuating pushrods 98, of which there arepreferably four, arranged circumferentially 90 degrees apart, areprovided to actuate the bands 96 between their expanded positions (asshown), in which they are positioned to anchor the distal tip 80 b tothe desired tissue site, and their retracted positions.

FIG. 15 illustrates another modified embodiment which is similar to thatof FIG. 14, and wherein like elements to those of FIG. 14 are designatedby like reference numerals, succeeded by the letter “c”. The onlydifference between this embodiment and the FIG. 14 embodiment is thatthe bands 96 c are split at their centers, to form protruding portions100, for the purpose of permitting further radial extension of each bandand to also permit the protruding portions 100 to attach themselves toadjacent tissue.

FIGS. 16 and 17 schematically illustrate still another modifiedmechanical fixation structure 94 d, comprising a linkage, which may besubstituted for the structures 94 and 94 c of FIGS. 14 and 15,respectively, wherein FIG. 16 illustrates the linkage in its retractedconfiguration and FIG. 17 illustrates it in its radially expandedconfiguration.

FIG. 18 schematically illustrates yet another modified mechanicalfixation structure 94 e, comprised of a plurality of radiallyretractable and extendable wires 102.

FIG. 19 schematically illustrates still another modified mechanicalfixation structure 94 f, of the bone anchor type, comprised of a nitinoltube 104 and radially expandable flaps 106.

In FIG. 20, there is shown another modified mechanical fixationstructure 94 g, comprised of a rolled stent which may be unrolled toexpand radially and provide an anchoring function by axially retractinga sleeve 108.

FIG. 21 shows still another modified mechanical fixation structure 94 hcomprised of a plurality of extendable wires 110.

FIG. 22 illustrates a modified mechanical fixation structure 94 i whichcomprises a radially expandable and retractable basket.

Any of the foregoing mechanical fixation structures may beinterchangeably employed in the embodiments of FIGS. 14 and 15, and itis within the scope of this invention to also employ other mechanicalfixation structures which are known conventionally for anchoring medicaldevices in the body.

Still another means for bonding the distal end of the instrument 78 tosurrounding tissue, which is within the scope of the present invention,is to apply RF energy to the tissue, using an electrosurgicalcoagulation element. The electrosurgical coagulation element maycomprise one of the existing electrosurgical elements 82 or 86, orpreferably another coagulation element 112 (FIG. 13) which may bedisposed on or near the bushing 90. Activation of the coagulationelement 1 12 for a short interval coagulates the tissue surrounding thetissue, thereby bonding the bushing to the tissue. Alternatively, theelement 112 could comprise a heating rod for cauterizing tissue, similarto the function of a branding iron, to produce the same type of bondingeffect by “sticking” the cauterized tissue to the distal end of theinstrument.

This approach may also be utilized in the localization wire embodimentsillustrated in FIGS. 1-12, by employing an electrosurgical coagulationelement on the distal end thereof, which is connected to a suitableelectrosurgical generator, or, alternatively, by employing an electricalheating element for cauterizing tissue.

While this invention has been described with respect to various specificexamples and embodiments, it is to be understood that the invention isnot limited thereto and that it can be variously practiced within thescope of the following claims.

1. A medical device comprising a tube having a distal end, a proximalend, and a longitudinal axis, the device being adapted for placement ofsaid distal end into a patient's body at a desired location, saidmedical device having affixation agent disposed on said distal end, thefixation agent being adapted for affixing the distal end of said medicaldevice at said desired location. 2-48. (canceled)
 49. A medical devicefor localization of tissue at a target site comprising: a. an elongatedshaft which has a distal shaft portion with a distal tip and a proximalshaft portion and which is configured for placement of the distal shaftportion into a patient's body at a desired target site; b. a tissuepenetrating distal tip on the distal shaft portion; c. at least oneelongated first fixation element which has a retracted and an expandedconfiguration, which has a first part that is secured to the distalshaft portion and that extends away from the distal shaft portion in adistal direction in the expanded configuration and which has a secondpart with a free end that deploys into tissue in the expandedconfiguration to facilitate securing the distal shaft portion withintissue at the target site; and d. at least one elongated second fixationelement which has a retracted and an expanded configuration, which has afirst part that is secured to the distal shaft portion and that extendsaway from the distal shaft portion in a proximal direction in theexpanded configuration and which has a second part with a free end thatdeploys into tissue in the expanded coniguration to facilitate securingthe distal shaft portion within tissue at the target site.
 50. Themedical device of claim 49, wherein the tissue penetrating distal tiphas an electrosurgical cutting element to facilitate tissue penetration.51. The medical device of claim 50 wherein the electrosurgical cuttingelement is configured to be electrically connected to a RF energysource.
 52. The medical device of claim 50 wherein the electrosurgicalcutting element is spaced distal to the distal tip.
 53. The device ofclaim 49 wherein the distal shaft portion has a radially expandable,longitudinally oriented tissue cutting element having a first unexpandedconfiguration for delivery and a second radially expanded configurationfor cutting a tissue sample from target tissue.
 54. The device of claim53 wherein the tissue cutting element is configured to rotate about alongitudinal axis of the shaft to sever tissue from the tissue site. 55.The device of claim 53 wherein the tissue cutting element extendsradially a greater distance than the first and second fixation elements.56. The medical device of claim 53 wherein the longitudinally orientedtissue cutting element is an electrosurgical tissue cutting element. 57.The medical device of claim 56 wherein the electrosurgical tissuecutting element is secured to a source of RF electrical energy.
 58. Themedical device of claim 53 wherein the longitudinally oriented tissuecutting element in the retracted configuration is seated within a slotprovided in the distal shaft portion.
 59. A device for separating andlocalizing a tissue specimen at a target site within a patient,comprising: a. an elongated shaft which has a distal shaft portion witha distal tip and a proximal shaft portion and which is configured forplacement of the distal shaft portion into a patient's body at a desiredtarget site; b. a tissue penetrating distal tip on the distal shaftportion; c. at least one elongated first fixation element which has aretracted and an expanded configuration, which has a first part that issecured to the distal shaft portion and that extends away from thedistal shaft portion in the expanded configuration and which has asecond part with a free end that deploys into tissue in the expandedconfiguration to facilitate securing the distal shaft portion withintissue at the target site; and d. a radially expandable, longitudinallyoriented tissue cutting element on the distal shaft portion having afirst unexpanded configuration for delivery and a second radiallyexpanded configuration for cutting a tissue sample from target tissue.60. The device of claim 59 wherein the first fixation element extendsdistally away from the distal shaft portion in the expandedconfiguration.
 61. The device of claim 60 including at least oneelongated second fixation element which has a retracted and an expandedconfiguration, which has a first part that is secured to the distalshaft portion and that extends away from the distal shaft portion in aproximal direction in the expanded configuration and which has a secondpart with a free end that deploys into tissue in the expandedconfiguration to facilitate securing the distal shaft portion withintissue at the target site.
 62. The device of claim 53, wherein thetissue penetrating distal tip has an electrosurgical cutting element tofacilitate tissue penetration.
 63. The medical device of claim 62wherein the electrosurgical cutting element on the distal tip isconfigured to be electrically connected to a RF energy source.
 64. Themedical device of claim 62 wherein the electrosurgical cutting elementis spaced distal to the distal tip.
 65. A method of performing a tissueacquisition procedure at a target site within a patient's body,comprising: a. providing a tissue acquisition device comprising a shafthaving a distal shaft portion with a tissue penetrating distal tip, atleast one fixation element which in an expanded configuration extendsaway from the distal shaft portion, which has a free end and another endsecured to the distal shaft portion proximal to the distal tip, and aradially expandable, longitudinally oriented tissue-cutting elementconfigured for cutting a tissue; b. advancing the distal shaft portionof the tissue acquisition device within a patient's body, so that thedistal shaft portion is disposed within the target site; and c.extending into tissue at the target site the free end of the at leastone fixation element so that the distal shaft portion becomes securedwithin tissue at the target site; d. radially expanding the tissuecutting element away from the distal shaft; and e. rotating the expandedtissue cutting element to separate tissue from the tissue site.
 66. Themethod of claim 65 wherein the tissue acquisition device has at least afirst fixation element which in an expanded configuration extendsproximally away from the distal shaft portion and at least a secondfixation element which in an expanded configuration extends distallyaway from the distal shaft portion so the free ends thereof engagetissue at the target site.
 67. The method of claim 65 wherein RF energyis delivered to the radially expanded tissue cutting element to severthe tissue specimen from the target site.
 68. A method of tissuelocalization at a target site within a patient's body, comprising: a.providing a tissue localization device comprising a shaft having adistal shaft portion with a tissue penetrating distal tip, at least onefirst fixation element which in an expanded configuration extends awayfrom the distal shaft portion in a proximal direction, which has a freeend and another end secured to the distal shaft portion proximal to thedistal tip, and at least one first fixation element which in an expandedconfiguration extends away from the distal shaft portion in a proximaldirection, which has a free end and another end secured to the distalshaft portion proximal to the distal tip; b. advancing the distal shaftportion of the tissue localization device within a patient's body, sothat the distal shaft portion is disposed within the target site; and c.extending into tissue at the target site the free ends of the first andsecond fixation elements so that the distal shaft portion becomessecured within tissue at the target site.
 69. The method of claim 68wherein the tissue penetrating distal tip is provided with anelectrosurgical cutting element and RF energy is delivered to theelectrosurgical cutting element as the distal shaft portion is advancedwithin the patient until the distal tip is distal to the target site.70. The method of claim 68 wherein at least one of the fixation elementsof the tissue acquisition device are configured for penetrating tissueat the target site.
 71. The method of claim 68 wherein when the at leastone fixation element is in its contracted configuration while the deviceis advanced to the target site.